<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Document</title>
    </head>
    <body>
        
    </body>
</html>
<script>
    
    function func() {
        console.log(999);
    }



</script>
<script>
    function test() {
        console.log(666);
    }

    var a;
    // function 函数名(形参类表) {
    //     代码块
    //     return;
    // }

    function sum(a, b) {
        return a + b;
    }

    var r = sum(5, 6);
    console.log("r = " + r);

    var b = a;

    a = 5;
    console.log(b);

    test();

    


    func();




</script>
